Went out to my rock pile and pulled out a couple old pieces of rock that looked bake. I collected both of these so I know they are natural. The small piece is from the Owyhee's in eastern Oregon. The big piece comes from an area west of the Willow Creek jasper mine in Idaho. There was a lot of it and I thought I hit a home run until I cut some. It is all very boring inside and no sign of heat. It does not polish. ???? If this material got hot enough to melt the outside I do not think the inside could be as white as most of these pieces. It has a waxy feel to the skin. While it is hard on the outside it breaks pretty easy. I think the surface is just a natural finish that is mineral related, not heat. I do agree there is a lot of heated material out there. neal